Hearing loss differentially affects thalamic drive to two cortical interneuron subtypes
Hearing loss differentially affects thalamic drive to two cortical interneuron subtypes
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DOI：
10.1152/jn.00182.2013
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发表时间：
2013-08-01
影响因子：
2.5
通讯作者：
Sanes, Dan H.
中科院分区：
文献类型：
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作者：
Takesian, Anne E.;Kotak, Vibhakar C.;Sanes, Dan H.
感觉剥夺，如发育性听力损失，导致整个中枢神经系统的突触和膜特性的调整。这些变化被认为是对声音诱发活动减少的补偿。该模型预测，代偿性变化应该是协同的，沿着沿着每个功能通路。为了验证这一观点，我们研究了兴奋性丘脑驱动两种类型的皮质抑制性中间神经元，显示不同的影响，响应发育性听力损失。由快速尖峰（FS）细胞产生的抑制性突触因听力损失而减弱，而由低阈值尖峰（LTS）细胞产生的抑制性突触保持强大，但显示出更大的短期抑制（Takesian et al. 2010）。从丘脑皮质脑切片中的FS或LTS中间神经元进行全细胞记录，并分析内侧膝状体（MG）诱发的突触后电位。听力损失后，MG诱发的FS细胞的净兴奋电位小于正常值，但LTS细胞的净兴奋电位大于正常值。此外，MG诱发的兴奋性电位表现出较少的短期抑郁症FS细胞和更大的短期抑郁症LTS细胞。因此，剥夺诱导的兴奋性突触对抑制性中间神经元的调节是细胞类型特异性的，并且与抑制性传入神经元的变化平行。
Sensory deprivation, such as developmental hearing loss, leads to an adjustment of synaptic and membrane properties throughout the central nervous system. These changes are thought to compensate for diminished sound-evoked activity. This model predicts that compensatory changes should be synergistic with one another along each functional pathway. To test this idea, we examined the excitatory thalamic drive to two types of cortical inhibitory interneurons that display differential effects in response to developmental hearing loss. The inhibitory synapses made by fast-spiking (FS) cells are weakened by hearing loss, whereas those made by low threshold-spiking (LTS) cells remain strong but display greater short-term depression (Takesian et al. 2010). Whole-cell recordings were made from FS or LTS interneurons in a thalamocortical brain slice, and medial geniculate (MG)-evoked postsynaptic potentials were analyzed. Following hearing loss, MG-evoked net excitatory potentials were smaller than normal at FS cells but larger than normal at LTS cells. Furthermore, MG-evoked excitatory potentials displayed less short-term depression at FS cells and greater short-term depression at LTS cells. Thus deprivation-induced adjustments of excitatory synapses onto inhibitory interneurons are cell-type specific and parallel the changes made by the inhibitory afferents.